<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

<form id="register" action="#" >
    <input type="text" name="username" />

    <input type="submit" value="提交">
</form>

<script>
    // 给提交按钮绑定事件  返回false 提交失败，返回true提交成功




</script>

</body>
</html>